The invention relates to a powered hand tool for trimming door jambs and casings. Door jambs and casings are often installed before the flooring is laid and for that reason the door joints and casings must be trimmed to a predetermined distance above the sub-floor in order to install the flooring which extends beneath the door jambs and casings. U.S. Pat. Nos. 5,967,013 and 6,449,852 describe jamb saws described as useful for door jamb and casing trimming including trimming in corners. The jamb saws shown in the before mentioned patents and door jamb saws currently marketed are deficient in adaptability for connection to a power unit, are awkward to hold and operate and are not convenient to adjust the height of cut.